Answer your cell phone or text during the interview.
Set your coffee cup you got from Starbucks on the interviewer's desk and put your feet up on the desk. (Yes! It happened!)
Tell the interviewer you need a cigarette break.
Be 15 minutes late to the interview and say casually "Hi, I'm just 15 minutes late! I'm sure you WON'T mind!"
Cry or tell your tragic life story. (It's not "Oprah")
Ask when you qualify for a vacation.
When asked if you can start work tomorrow say "No. I've got a party to go to."
Ask the interviewer for a date.
Show up high or drunk and expect the interviewer not to notice.
Be completely unable to answer any questions from the resume or application you submitted...including where you last worked.
Ask for an advance on your salary if you are hired.
Demand to see the office you will get if you are offered a position, then inform the interviewer that "This will never work...it's bad Feng Shui."